McNary Dam
Encyclopedia
McNary Dam is a 1.4-mile (2.2-km) long concrete gravity run-of-the-river
dam
which spans the Columbia River
. It joins Umatilla County, Oregon
with Benton County, Washington
, 292 miles (470 km) upriver from the mouth of the Columbia at Astoria, Oregon
. It is operated by the U.S. Army Corps of Engineers' McNary Lock and Dam office. The dam is located a mile (2 km) east of the town of Umatilla, Oregon
, and 8 miles (13 km) north of Hermiston, Oregon
. The dam was originally planned to be named Umatilla Dam, but the Flood Control Act of 1945 renamed the dam in honor of Senator
Charles L. McNary
of Oregon
, who had died the previous year.
The dam provides for slackwater navigation, hydroelectric power generation, recreation, wildlife habitat, and incidental irrigation.
Bills for the construction of a dam were introduced in the United States Congress
as early as 1931. The United States House of Representatives
rivers and harbors committee initially approved the project in April 1941; navigation, power generation
, and national security were the major reasons cited for construction of the dam. Construction began in 1947, and was completed in 1954. Activation of all generating units was completed in 1957. Its capacity is 980 MW. There are two fish ladder
s for salmon
and steelhead
passage, one on each shore of the dam. The Washington side also has an 86 foot (26 m) wide, 683 foot (208 m) long navigation lock that lifts boats an average of 75 feet (23 m). The dam flooded the Umatilla Rapids, forming a reservoir called Lake Wallula
. The lake extends 64 miles (103 km) up the Columbia to the US DOE
Hanford Site
. It also extends up the Snake River
to the Ice Harbor Dam
.
This dam has a unique feature: two additional turbines whose purpose is to power the dam itself. That is, this dam is entirely self-sustaining; and if some large event caused the entire grid to go down, McNary would be key in getting it back on. These two "station service" turbines are only capable of providing about three MW, compared to the 70 MW of the other 14 turbines. These two turbines alternate service duty to provide the dam with its energy requirements.
McNary Dam is part of the Columbia River Basin
system of dams.
Stats:
Run-of-the-river hydroelectricity
Run-of-the-river hydroelectricity is a type of hydroelectric generation whereby a considerably smaller water storage called pondage or none is used to supply a power station. Run-of-the-river power plants are classified as with or without pondage...
dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
which spans the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...
. It joins Umatilla County, Oregon
Umatilla County, Oregon
Umatilla County is a county located in the U.S. state of Oregon. It is included in the 8 county definition of Eastern Oregon. The county is named for the Umatilla River. In 2010, its population was 75,889...
with Benton County, Washington
Benton County, Washington
Benton County is a county located in the south-central portion of the U.S. state of Washington. The Columbia River makes up the north, south, and east boundaries of the county. In 2010, its population was 175,177. The county seat is Prosser, and its largest city is Kennewick...
, 292 miles (470 km) upriver from the mouth of the Columbia at Astoria, Oregon
Astoria, Oregon
Astoria is the county seat of Clatsop County, Oregon, United States. Situated near the mouth of the Columbia River, the city was named after the American investor John Jacob Astor. His American Fur Company founded Fort Astoria at the site in 1811...
. It is operated by the U.S. Army Corps of Engineers' McNary Lock and Dam office. The dam is located a mile (2 km) east of the town of Umatilla, Oregon
Umatilla, Oregon
Umatilla is a city in Umatilla County, Oregon, United States. It is named for the Umatilla River, which enters the Columbia River on the side of the city. The river is named after the Umatilla Tribe. The city is located on the south side of the Columbia River, and is located on U.S...
, and 8 miles (13 km) north of Hermiston, Oregon
Hermiston, Oregon
As of the census of 2010, there were 16,745 people, 4,964 households, and 3,360 families residing in the city. The population density was 2,035.4 people per square mile . There were 5,383 housing units at an average density of 832.9 per square mile...
. The dam was originally planned to be named Umatilla Dam, but the Flood Control Act of 1945 renamed the dam in honor of Senator
United States Senate
The United States Senate is the upper house of the bicameral legislature of the United States, and together with the United States House of Representatives comprises the United States Congress. The composition and powers of the Senate are established in Article One of the U.S. Constitution. Each...
Charles L. McNary
Charles L. McNary
Charles Linza McNary was a United States Republican politician from Oregon. He served in the Senate from 1917 to 1944, and was Senate Minority Leader from 1933 to 1944. In the Senate, McNary helped to pass legislation that led to the construction of Bonneville Dam on the Columbia River, and worked...
of Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, who had died the previous year.
The dam provides for slackwater navigation, hydroelectric power generation, recreation, wildlife habitat, and incidental irrigation.
Bills for the construction of a dam were introduced in the United States Congress
United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....
as early as 1931. The United States House of Representatives
United States House of Representatives
The United States House of Representatives is one of the two Houses of the United States Congress, the bicameral legislature which also includes the Senate.The composition and powers of the House are established in Article One of the Constitution...
rivers and harbors committee initially approved the project in April 1941; navigation, power generation
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
, and national security were the major reasons cited for construction of the dam. Construction began in 1947, and was completed in 1954. Activation of all generating units was completed in 1957. Its capacity is 980 MW. There are two fish ladder
Fish ladder
A fish ladder, also known as a fishway, fish pass or fish steps, is a structure on or around artificial barriers to facilitate diadromous fishes' natural migration. Most fishways enable fish to pass around the barriers by swimming and leaping up a series of relatively low steps into the waters on...
s for salmon
Salmon
Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...
and steelhead
Rainbow trout
The rainbow trout is a species of salmonid native to tributaries of the Pacific Ocean in Asia and North America. The steelhead is a sea run rainbow trout usually returning to freshwater to spawn after 2 to 3 years at sea. In other words, rainbow trout and steelhead trout are the same species....
passage, one on each shore of the dam. The Washington side also has an 86 foot (26 m) wide, 683 foot (208 m) long navigation lock that lifts boats an average of 75 feet (23 m). The dam flooded the Umatilla Rapids, forming a reservoir called Lake Wallula
Lake Wallula
Lake Wallula is a reservoir on the Columbia River in the United States, between the U.S. states of Washington and Oregon. It was created in 1954 with the construction of McNary Dam. It reaches from McNary Dam near the city of Umatilla, Oregon, to the Tri-Cities of Washington.-See also:* Wallula...
. The lake extends 64 miles (103 km) up the Columbia to the US DOE
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
Hanford Site
Hanford Site
The Hanford Site is a mostly decommissioned nuclear production complex on the Columbia River in the U.S. state of Washington, operated by the United States federal government. The site has been known by many names, including Hanford Works, Hanford Engineer Works or HEW, Hanford Nuclear Reservation...
. It also extends up the Snake River
Snake River
The Snake is a major river of the greater Pacific Northwest in the United States. At long, it is the largest tributary of the Columbia River, the largest North American river that empties into the Pacific Ocean...
to the Ice Harbor Dam
Ice Harbor Lock and Dam
Ice Harbor Lock and Dam is a hydroelectric, concrete gravity run-of-the-river dam on the Snake River in Walla Walla and Franklin counties in the U.S. state of Washington. The dam is located 8 miles northeast of the town of Burbank and 12 miles east of Pasco, river mile 9.2...
.
This dam has a unique feature: two additional turbines whose purpose is to power the dam itself. That is, this dam is entirely self-sustaining; and if some large event caused the entire grid to go down, McNary would be key in getting it back on. These two "station service" turbines are only capable of providing about three MW, compared to the 70 MW of the other 14 turbines. These two turbines alternate service duty to provide the dam with its energy requirements.
McNary Dam is part of the Columbia River Basin
Columbia Basin
The Columbia Basin, the drainage basin of the Columbia River, occupies a large area–about —of the Pacific Northwest region of North America. In common usage, the term often refers to a smaller area, generally the portion of the drainage basin that lies within eastern Washington.Usage of the term...
system of dams.
Stats:
- Location: 45.9298548 -119.2961275
(45°55′47"N 119°17′46"W) - Altitude: 344 feet (104.9 m) above sea level
- Height: 183 feet (55.8 m)
- Length: 7365 feet (2,244.9 m)
- Navigation lock:
- Single-lift
- 86 feet (26.2 m) wide
- 683 feet (208.2 m) long
- Powerhouse
- Fourteen 70,000-kilowatt units
- Total capacity: 980 megawatts
- Overload capacity: 1,127 MW
- Spillway
- Gates: 22
- Length: 1310 feet (399.3 m)
See also
- Hydroelectric dams on the Columbia RiverHydroelectric dams on the Columbia RiverHydroelectric dams on the Columbia River and its tributaries in North America.- Mainstem Columbia dams :-Snake River:-Pend Oreille-Clark Fork–Flathead:-Kootenai River:-See also:...
- McNary Dam HeliportMcNary Dam HeliportMcNary Dam Heliport is a private heliport located 1 mile south of Umatilla in Umatilla County, Oregon, USA....
- Hat Rock State ParkHat Rock State ParkHat Rock State Park is a state park in the U.S. state of Oregon, administered by the Oregon Parks and Recreation Department. The park is located off the east side of U.S...